In the fields of clinical laboratory tests and diagnostic drugs, measurement methods involving utilizing immune reactions are widely performed. In this context, there is a demand for an increase in sensitivity of a test, and an improvement in sensitivity of a clinical laboratory test or a diagnostic drug has become a significant task. In order to increase the sensitivity, as a mode of detection, a method involving using an enzymatic reaction with peroxidase or alkaline phosphatase is being replaced by a method involving using fluorescence or chemiluminescence. It is said that the use of fluorescence or chemiluminescence as the mode of detection allows confirmation of the presence of one molecule of a test object substance in theory. In actuality, however, target sensitivity has not been achieved.
As one of the factors affecting the detection sensitivity in measurement utilizing an immune reaction, there is given non-specific adsorption of an antibody or an antigen serving as a measurement object, or a labeled form thereof to be utilized for the measurement onto an immune reaction vessel or a solid phase surface. In addition, when a substance in which a plurality of kinds of biomolecules coexist, such as serum, plasma, cell extract, and urine, is used as a specimen, occurrence of a noise due to non-specific adsorption of an unspecified large number of coexisting substances, such as various proteins, onto the immune reaction vessel or the solid phase surface also serves as a factor in inhibiting the increase in sensitivity.
In order to prevent such non-specific adsorption, heretofore, there has been used a method of suppressing non-specific protein adsorption by allowing a protein of biological origin, such as bovine serum albumin, casein, or gelatin, that is not involved in the immune reaction to adsorb onto the immune reaction vessel or the solid phase surface. However, when the protein of biological origin, such as bovine serum albumin, is used, there are restrictions, such as a problem of biological contamination typified by BSE, a lot-to-lot variation, a storage temperature, and an expiration date. Accordingly, there has been desired development of a non-specific protein adsorption-suppressing agent containing, as a main component, a chemically synthesized product capable of solving those problems.
As the non-specific protein adsorption-suppressing agent containing a chemically synthesized product as a main component, the following has been disclosed.
In Patent Literature 1, there is a disclosure of a “blocking agent containing polyvinyl alcohol.” In Patent Literature 2, there is a disclosure of a “protein adsorption-preventing agent containing a 2-methacryloyloxyethylphosphorylcholine polymer.”
Those methods each express an effect solely by allowing the chemically synthesized product serving as the non-specific protein adsorption-suppressing agent to physically adsorb onto the solid phase surface. Those techniques can preclude non-specific adsorption onto the solid phase surface to some extent, but have not yet been sufficient. Further, a specimen-treating liquid of the present invention is not disclosed or suggested.